The legal production, sale and use of cannabis for medical purposes is becoming more prevalent in many countries, including the United States and Canada. It is important for medical cannabis growers, dispensaries and end-users to know the concentration of certain cannabinoids, particularly delta-9-tetrahydrocannabinol (THC) in specific plant samples—such information can be important for strain development, for optimizing production/growing cycles, for complying with jurisdiction-specific legal requirements, and for other quality control purposes. Quantification of cannabinoids in a sample generally requires a laboratory test, for instance using gas chromatography, which can be expensive and generally requires time to send the sample to an appropriate lab and wait for the results. Home-based tests, such as Alpha-Cat, have been developed using thin-layer chromatography, however this test is still quite complex for the average untrained user, and the quantification resolution of the test is limited.
Reagents are known in the art that react chemically with CBD, under specific reaction conditions, to create a color change. Mechoulam (Tetrahedron 24(16): 5615-5624, 1968) teaches that CBD, when contacted with 5% ethanolic potassium hydroxide (KOH) is converted to quinone, which has a purple color.
U.S. Pat. No. 4,771,005, issued to Spiro, teaches methods for positive/negative cannabinoid detection in human sample using a diazonium salt, for instance Fast Blue BB.
WO/1989/009395 (published in the name of Fraser and Johnson) teaches a test paper for positive/negative cannabinoid detection using diazonium salt, for instance Fast Blue BB.
U.S. Pat. No. 8,124,420, issued in the name of Amisar, teaches a test paper and kit for detection and/or identification of a range of drugs of abuse, which may include cannabinoids, and the test paper may include a diazonium salt, for instance Fast Corinth V.
Fischedick et al. (2009 Phytochem Anal 20:421-6) teaches a method for quantifying cannabinoids in a sample using high performance thin layer chromatography (HPTLC).